2.4. Synthesis of ETC-Au-Fe3O4 NPs
ETC was synthesized according to our previous study [13]. 2 mL
Au-Fe3O4 NPs (12 mg/mL) in CHCl3 was added to 5 mL of CHCl3.
The solution was then mixed with a solution of 15 mg ETC, 20 mg
mPEG-SH and 30 mg Na2CO3 in 5 mL water. The mixture was stirred
for 12 h at room temperature. The ETC-Au-Fe3O4 NPs were then
separated by centrifugation and re-dispersed in water.